Messages in this thread | | | Date | Sat, 10 Oct 2009 20:37:20 +0200 (CEST) | From | Thomas Gleixner <> | Subject | infiniband BKL leftovers |
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Roland,
I'm looking into removing cycle_kernel_lock() from drivers/infiniband/hw/ipath/ipath_file_ops.c .
cycle_kernel_lock() was pushed down into open functions to "emulate" the previous BKL protected semantics by "serializing" the open function against driver init in progress. Nobody knows how effective this "serialization" was in reality. :)
This protection is not necessary when everything what might be needed by write/aio_write/poll/mmap should be in place before ipath_user_add() creates the device node.
But looking at the callsite ipath_init_one() I'm not so sure about that.
At the end of ipath_init_one() I see:
ipath_device_create_group(&pdev->dev, dd); ipathfs_add_device(dd); ipath_user_add(dd); ipath_diag_add(dd); ipath_register_ib_device(dd);
ipath_user_add() is called before ipath_register_ib_device() which registers the device with the infiniband core. That makes me wonder whether the device node is really ready to use right after it is created.
Aside of that I noticed that all the functions above have elaborate error pathes, but non of the return values of these functions is ever checked. Intersting approach :)
Thanks,
tglx
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